Weighing scale



FIG. 1 is a perspective view of a weighing scale showing our new design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a right-side elevational view thereof, an elevational view of the left side being a mirror image;

FIG. 5 is a front view thereof; and,

FIG. 6 is a rear view thereof.

The portions shown in dashed lines form no part of the claimed design. 

The ornamental design for a weighing scale, as shown and described. 